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We have existing (if somewhat unproven) antibodies, an underserved market with a significant need (if you can save insurers the use of a CT/MRI scan AND improve medical outcomes by allowing quick disambiguation between strokes or other sources of dizziness then it is a win/win), and the need for a mobile, multiplexed and quantitative system.

Interestingly, Biosite tried to do it, then pulled the test. While obviously indicating some difficulties in pulling this off, it also demonstrates a recognised commercial potential.

We'd like to give a special mention to Eswar for a) the serious amount of work he's put in and b) the most lateral idea of all the submissions - really enjoyed thinking about his perfume idea."The bottom line: We're looking for a large enough market to justify manufacturing setup and regulatory costs where consumers would be prepared to pay $15+ per test. The unique features to exploit are multiplexing of dozens of quantitive tests combined with rapid & simple point-of-care use with minimal sample prep – carefully check out the full comparison to competing methods in the table below.
The vast majority of biosensors today are based on some form of optical readout to get the results you want. You usually have a choice between inexpensive (but non-quantitative) methods such as lateral flow tests (e.g. pregnancy tests), which just show you a blue line if positive, or more sensitive tests that can tell you how much of the analyte is present using specialised optical equipment. These quantitative tests generally require several extra wash steps and additional reagents and are carried out by labs or on specialised microfluidic or robotic platforms. We wanted to develop a sensitive, quantitative technology that doesn’t require expensive platforms but instead:

Could be read using a low-cost smartphone or laptop accessory (<$20);

Works with a small amount of sample (~10 microlitre, such as a tiny drop of blood, urine or saliva)

Requires no (or just one) washing steps.

Runs several different tests on the same sample simultaneously.

Is as easy to use as a pregnancy test.

How the e-Gnosis system will work: a small chip with the ability to test for dozens of analytes slots into a reusable reader, which in turn connects to a smartphone, computer or tablet.

And that’s what we’ve done with our e-Gnosis chip! We’re now looking for both attractive markets in the medical diagnostics space or in the potentially much easier to enter consumer space. Please read the “Your mission” section below carefully!

The table below compares our device to existing test categories. The e-Gnosis chip combines the advantages of quantitative, multiplexed tests with the accessibility of a low-cost, mobile reader – which should make it very attractive to consumer applications. However we need to find one where we can reach high volumes to justify setup costs and where a cost of goods sold of $6-8 per test is realistic.

Your missionWe’re looking to find a market that is large and has less regulatory tape than medical diagnostics.

We’ve been looking at the field of medical diagnostics for a while, but the point-of-care market is highly competitive, fragmented into relatively small markets, with high entry barriers in the form of FDA/EMA approval. So for any medical diagnostic we’d need a large market, where our device’s unique features (multiplexing, rapid & simple point-of-care use without sample prep) offer a very significant competitive advantage, and can justify the high barrier costs for approval.

We’d be very interested to hear ideas about a consumer market to prove the device commercially, keeping in mind:

While the chip-manufacturing part of the process is cheap, the cost/test is unlikely to ever fall below $6-8 due to functionalization and assembly. We need an application where customers would pay enough to allow a reasonable profit margin.

What would be the market entry route? Who’d be our commercial partners? What are the competing devices and their price? How would distinguish ourselves against these?

Potential applications
We have so far proven the concept and are now working on simplifying the chip and applying to existing assay (pregnancy tests first). We think immunoassays in general are a good starting point, as they do not require complex sample preparation. Other assay types are possible as well though (see Key Features below or the background section above).
A large variety of existing immunoassays (and other tests) can be moved onto the e-Gnosis chip surface, including:

Allergies (by looking for antigen specific IgE's in a multiplexed assay, currently done by companies such as Phadia)

Cancer (e.g. Prostate-specific antigen)

Infectious disease

Stress testing (using cortisol, testosterone and alpha amylase).

Key features

Detection based on large variety of probe-analyte interactions

antibody-antigen

complimentary DNA strands

aptamer-protein

Note: For very small molecules, a competitive assay format or secondary antibodies have to be used to cause a large-enough constriction of the pores.

Quantitative & sensitive: In trial detected streptavidin (using biotin as a probe) down to 5x10-11 M, and accurately determined the size of streptavidin (about 5 nm). Potential for further improvement.

Schematic of the operating principle of the e-Gnosis chip. Click to enlarge.

Here’s how it works:
Two electrodes running at right angles to each other are separated by an insulator (silicon oxide, shown in yellow below). Hundreds of thousands of nanometre sized wells (we call them nanowells) are formed through this structure (via CsCl island lithography), so that one electrode is at the bottom, and the other at the top of the wells. The wells are ~ 100 nm in diameter, and around 200 nm deep (although these dimensions can be varied). The area where the top and bottom electrodes overlap is what we call a pixel, and each pixel is in essence a huge array of nanoelectrodes with a very small electrode spacing. Arrays of nanoelectrodes have many advantages over macroelectrodes of equivalent electrode surface area, chiefly a higher signal to noise ratio and therefore a lower limit of detection in electrochemical analysis (Prof. Madou has some great lecture slides on electrochemistry and scaling). Our chip could be used for tests such as the quantitation of pharmaceutical metabolites in urine, so if you have an idea for a electrochemical based test, let us know!

We go one step further and rather than analysing electrochemical reactions, measure the binding of an analyte molecule (could be a pregnancy hormone, cancer marker etc) to a probe molecule (e.g. an antibody).

We stick probe molecules (we have used biotin to bind streptavidin, but now are working on using antibodies), which bind the analyte we are looking for, to the inside of the pores. We then place a droplet of sample together with a redox couple (e.g. Ferri/Ferrocyanide) on the chip and apply a voltage. The redox couple is oxidised at one electrode, diffuses over to the other electrode and is reduced there. This results in a steady state where the current that can flow between the electrodes is dependent on the diameter of the nanowells. If the molecules we are looking for are present in the solution, they bind to their complementary probe molecule, and reduce the diameter of the nanowells and therefore the current that can flow between the electrodes at a given voltage. The rate of the current drop allows us to deduce the analyte’s concentration. We can also do the reverse, where the pores’ opening-up creates the signal, e.g. by attaching enzyme-degradable peptides to the pore walls. Competitive immunoassays are another possibility.

In order to prevent the electrodes from fouling over time, we frequently inverse the potential applied to the electrodes, which has a cleaning effect and makes sure the signal change we see is from the binding to the inside of the wells and not from non-specific adsorption to the electrodes. We also use control pixels that do not have active probe molecules and so cannot bind to anything specifically, but have the same functionalisation as the active test pixels. These control pixels provide a background signal. By subtracting the control pixel signal from an active pixel signal we get the signal change due to a specific binding reaction.

We currently have a chip with just twelve pixels, but at production scale, it's possible to fit in excess of 100 pixels on a 3x3 mm chip, each of which can in theory detect a different compound.

The story behind the science

I’m Peter Kollensperger and I’m working with Prof. Green in the Optical and Semiconductor Devices Group of the Electrical and Electronic Engineering Department at Imperial College London.

My research to date has focused on the use of nanotechnology for biosensing applications, but my overarching interest is in making diagnostic/sensing technologies more accessible both to doctors and the general public.

The combination of scalable nanotechnology and the hugely parallel processing of semiconductor foundries holds great promise for the area of biosensors and we are looking for applications where the end-user wants to get results on the go without spending a large upfront amount on a reader. This can be in medical diagnostics, but ideally would be in an underserved consumer market where the combination of properties of our chip can make a real difference.

Have you benchmarked your sensor for any existing Immuoassay(Eg. PSA or any protein-protein interaction) ? Additionally for streptavidin detection, did you immobilize botin and detect streptavidin, or the other way around.

Hi Srivatsa
We're working on benchmarking for hCG now. For biotin streptavidin, biotin was immobilised and streptavidin was detected. Due to the binding pocket in streptavidin I doubt there'd be a large enough signal change the other way round

Correct me if I'm wrong here but the difficult operation in this is picking out what to functionalize to the wells .... right? So the challenge is to find particular applications for which we have simple / known functionalization which will quantify some bio/other marker of interest. So that being said... Is there a set of pre existing chemistries ... or do you seek to develop these per market?

Thats right - what's an attractive market, taking into account the various tests that already exist.
If there isn't a probe, but there is a confirmed marker, it would be possible to generate a suitable probe.

What data is returned from a test, I understand that the device is use once (then incur the cost again/dispose?) but what does the test tell you, does it target a particular substance/structure or can it return more general information that can be analysed to determine a great deal of information? As with for example protein scan.

Hey Alan, the info you get out is essentially based on how much the pores are obstructed by the binding of the analyte to its walls. That means you can only really get concentration of the substance which specifically binds to the "hook" attached to the pore wall (and potentially the size of the analyte).

This is a neat idea. The problem might be sample size. It appears the detection limit is in the low pM range from what I read, (10^-11) Is this correct? I believe the problem with antibody based detection is the lack of a quality bio-marker. So detection of cancerous proteins etc. is a little difficult. No matter what you are going to need to amplify your sample as your detection limit is rather high. The best detection would be of oligonucleotides as these are easily amplified. You could then use biotin modified probe oligonucleotides to line your channels, and hybridize for detection. Sequencing is gonna be the method of choice in the future, so your best bet is at detection of pathogens, either bacteria or virus. You could do multiple sequences or just one for probing. This would be really useful at veterinary clinics or any medical office where a pathogen is the suspected culprit. You could detect different resistance markers instead of growing bacteria on dishes, saving people money.

How about using the e-Genosis chip for veterinary diagnostics? The competition for this market would be significantly lower since, to the best of my knowledge, there aren't any big animal care technology providers (in fact some vet practices often use human devices). Having spoken to a few vets, there seems to be a need for low-cost on-site testing of blood and urine. Currently, many vet practices seem to ship their samples to bigger sites, which makes the process time-consuming and more expensive. Additionally, a portable device for basic blood and urine testing would be of particular use to vets who have been called on site, e.g. diagnostics of farming animals or in the equine world.

Thanks to Mr. Olivier Pasquier's info of food testing cost.
There are many news of contaminated food or illegal food additives.
I notice the need of large scale speed testing of food additives in border health control
or customs, or even supermarket chain in western countries and China.
This test helps to assure the companies brand of quality, build customer confidence,
and avoid heavy legal liability. The situation is especially stringent in China where people are willing to spend more on food confidence.

Could your technology be used in the sports/dietary supplement market? By analysing blood or urine chemistry one could recommend what was lacking in that persons diet e.g. post exercise (I could see the professional sports world being happy to spend $15+ to tailor recovery drinks to their athletes body chemistry). Or provide an avid dieter spending large amounts of money on vitamin pills a clear image of what they actually needed.
If it was easy to use and plugged into a smartphone then I could see it also making an impact in the sizeable amateur sports world too.
Partners could include any of the major sports brands or supplement providers.

There is a market where millions of biochemical tests are made every week with no regulation. This is the Drug Discovery market. HTS is around 20 cents per well for a simple read-out (Y/N answer). If you can attach easily a protein of interest into your pore, you can screen if a compound (new molecule) can bind to this protein in measuring the conductivity, right ? Then you have a HTS device. In a quantitative way, that makes the difference. To reach your market, you would need to adapt your technology to a 384/1536 SBS format (or more), so a little different from your chip there. Bu then this is a multibillion market !

The issue with large markets is you are competing with existing solutions, and having the only advantage of low cost isn't very attractive. Aiming at needs which are not well satisfied might yield a better outcome, but you've got risk upfront. For example - detecting accurate ovulation time (don't ask me how...) would be a benefit to a large population currently using thermometers... Then there's alcohol meters (already on the market and multi use), bad breath testers (market size uncertain), noxious gas detectors - multi use, but sensors have relatively short lifetime. Then for the medical side, maybe you can look at applications overseas in countries where cost is an important factor and regulation is much less stringent. Could be distributed through Medcins sans frontiers, or WHO.

There are extreme high demands of quick first-level food testing in country borders and big supermarkets around the world, including Europe and China. Believe volume is high and regulation requirement is much lower than medical industry.

Could this technology be combined with the droplet orchestrator (another interesting Marblar Challenge) to make the e-Gnosis chip into a multi-use device? The idea being to use up a fraction of the active area on the chip each time in order to reduce overall cost per test and therefore open up many more market opportunities.

Multi-use is a great idea, but looking at the droplet orchestrator it seems to require quite a bit of equipment to use, and we think our chip is more suited to a mobile environment. With the droplet orchestrator, you already have optical equipment and could essentially serially run a number of tests from a small sample through one detector, and because they are spatially separated use a single fluorophore marker to quantify the analyte in each droplet (maybe using FRET or BRET to get around washing steps?)

I can see the idea behind developing a mass consumer market that does not involve all the fee seekers of the regulatory process. Unfortunately all the ideas put up so far look as though they would require high cost compliance.

I thought the idea of self testing for colds/flu etc would be good if there were no regulatory overheads. Also unfortunately I can't think of any suggestion at the moment. Maybe others can. I hope so.

I have done this before, but got shot down. So, hopefully, I am doing this right.

I would be interested in having this technology applied to, for example, moisture and mold detection. Currently, mold detection/moisture detection in Finland can cost upwards of 500 to 100 Euros, ca. 700 to 1250 USD. Whenever a family or person is interested in buying a new apartment or house, this can become an issue and deter one from entering into an agreement. If there were a way to perform a test with, say, the e-Gnosis chip at the heart, then this could greatly reduce this cost (and put some companies out of business).

Could this also not be applied to detecting gas leaks in-home?
Or, detecting other airborne pathogens?

Still on the mold detection...my family recently had to go through the painful process of having mold samples taken. The challenge is or was that the apartment was newly constructed and any water damage that has been done is or was buried either behind paint or sheet rock. Also, in the kitchen, there may be mold or water damage but the cabinetry would hide that.

Hi Tarwin,
The washing step(s) in current ELISAs are carried out after sample addition (to remove excess unbound sample and non specific proteins after a fixed incubation time), and then again after adding the labelled antibody (to remove unbound labelled antibody).
On our device we may incorporate a washing step after sample addition to remove any nonspecifically bound analyte or particulates.

I am also assuming that your technology could be used to hit hard at the current types of devices that require - regular retesting. Eg: Fertility.

If your device can be configured to be purchased once, and had 10,20,30 channels for the same antibody combination it becomes and extremely low cost device that could be disruptive for those who currently sell single devices. eg: fertility.

By your measure the device at $6-8 that could run a single test 28 times = $0.28 per test. A device that can run 100 tests - say ovulation then represents $0.08 per test (COGS).

Can you cram more channels per area on your current layout or do you think this is at an optimum?

Well, the question would be how to access the different channels at each time point. You have a 3x3mm chip with 100 or so pixels - how would you make sure your sample at each point reaches the correct pixel (and only that one)? The technology is very much designed with the chips being single-use at the moment.

I will think that through - however the advantage of a 100 pixel re-usable chip changes the context of the platform ... Disruptive and challenging. A nano pipet immediately comes to mind, or a circular array using similar technology for read/write from hard-disks.

Hm, I'm not quite sure that solves the issue of making the pixels individually addressable. I think the best thing would be to focus on the capabilities of the device as it is and finding the best way to exploit those before thinking of improvements that could happen down the road.

Tim Tim,
I really like the idea of making it multi-use, as you say the cost-per-test would come down drastically if this were possible.
We looked at several ways of doing this, e.g laminate covers with integrated wires that could be shorted to open a section of the chip at a time, mechanical access etc. However manufacturability is key and ideally you'd like to be able to use an existing process rather than building your own plant to make this happen.
As Gabriel says, accessing each individual pixel is difficult, with such a small pitch. Doubling the die/chip side length to allow more space for access, overlays etc quadruples the area and therefore the cost of the die. Another issue would be how to avoid contamination from one use to the next.

But with the right technology to interface to the chip, the ability to make it multi-use would be a game changer and I'd love to see more suggestions in this direction

I think of the cost of the die as negligible relative to the potential application, that is simply a cost equation that can be accounted for with current processes. The small pitch doesn't worry me too much that can be overcome in a number of ways.

One option is to go in the other direction, create an interface with the chip that is larger and lower cost and then focus on the delivery to the pixel read area of the chip to maximise scale of production. One might combine fabrication methods.

TimTim,
I still think this is a great idea, but after talking to a person with experience in die packaging, it seems the interfacing, whilst doable, is non-trivial. I'd really love to hear more about a low-cost way of accessing e.g. 100 pixels on a 3x3 mm die or so. I've looked at www.dolomite-microfluidics.... but this is still not really easy to use.

An easy way to place a fluidic pixel is to pad print it into position onto the silicon chip with pizo-electric movement for x,y co-ordinates. The pad is therefore disposable and low cost and can be attached to the sample collector, placed into the device, the sample pixel of fluid is picked up and then transferred to the 3x3mm chip at a known co-ordinate based on the last known free area. The Ep can be measured across the chip (scanned) before each action to gauge the free areas, the positions of pixel samples can be stored and logged into a memory chip sitting on the main device - manufactured at the same time as the main chip - or a simple side board using off the shelf surface mount components.

There could be many ways. Small problem - if the market is large - $100M

Here is a lower cost technology to make both the fluidic (destructive) channels & to also make your current chip. Top down manufacture so there is some rethinking to be done in the fab build. But the fundamentals are strong.

[1] The advantage is you can prototype at low cost (which points to getting your current chip cost down) & manufacture in batches as a startup- and remain flexible in the chips development. The time frame is 2 years for this technology to come to market. However your type of chip represents a model case study for conversion to this build down technology - which might mean applying it to your product sector .... immediately brings about game changing development costs - aka- costs that tumble by a magnitude 1000 fold.

Another novel technique to split a sample using a magnet and water repelling surface. [1] This could give quite precise measurement of volumes instantly - removing the need for complex wicking, one could have an initial flow that mixes the sample then splits it, sorts it via a manifold and pushes it onwards via multiple routes using the proximity of a magnet.

I have been waiting for this technology to pop up on Marblar. You say you are concerned about the cost of regulatory costs for medical diagnostics as a step. What if you could find a partner to overcome that problem ? Would that change your approach or are you fixed on going into lower barrier markets?

Is it a function of development within the University technology transfer programme and retaining control of spin-off's or would an outright licence deal be something you would want slapped on the table ?

Having spoken to Peter at length, the issue of regulatory cost is really one of a simple cost-benefit analysis in this case, which doesn't really depend on the method of execution (spin-out or licensing). If you'd expect to have to pay X to get a device to market, you need a large enough market to warrant paying X.

Peter/Imperial are seeing it more as a spin-out opportunity right now, but licensing is obviously a potentially attractive proposition as well in the right circumstances.

In the US, people routinely pay $200 to get a basic report on their racial makeup; i.e. percent Asian, percent African, etc. And the provider's tests are inconsistent. If you can provide a consistent and accurate result, even with probabilities like "10% probability of you being of 40% Irish descent", you may have a product.